Police said at least 22 people were killed and 59 others were injured at Manchester Arena in what is being treated as a "terrorist incident." Greater Manchester Police Chief Constable Ian Hopkins said children are among the deceased.

New York Gov. Andrew Cuomo said he's heartbroken, and that state law enforcement will step up security and patrols as a precaution. New York Police Commissioner James P. O'Neill tweeted that the city is closely monitoring the situation in Manchester.

I am heartbroken by the horrific explosion in Manchester. As a precaution, state law enforcement will step up security and patrols.